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A simple 16x16 dot animation from simple math rules

tixy.land

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Re: A simple 16x16 dot animation from simple math rules

#51

Post by LocalH »

chrisjj wrote: post #31
jakegmaths wrote: post #5

I loved tixy when I first discovered it a few years ago so created this https://www.mathsuniverse.com/tixy (with permission from the original author) with puzzles to solve on the tixy grid. I use it with my computer science students who get really into it.

> In computer graphics, the origin (0, 0) is top-left rather than bottom-left Umm...

What's wrong with that statement? It has historically and traditionally been true for raster displays, even if there do exist ways to use standard Cartesian-style coordinates with a computer.

Re: A simple 16x16 dot animation from simple math rules

#55

Post by Sharlin »

_def wrote: post #13
continuational wrote: post #10

Fun! https://tixy.land/?code=sin%28i%2Bt%29

i don't even know whats happening but its mesmerizing https://tixy.land/?code=sin%28i*t%2F128%29

It draws a slightly tilted sine wave gradient (i=16y+x so atan(1/16) ≈ 3.6°) whose frequency increases until it starts to alias due ro the limited resolution (cf. Nyquist sampling theorem) and exhibit what’s essentially the wagon wheel effect [1]. Nice illustration of signal processing fundamentals!

[1] https://en.m.wikipedia.org/wiki/Wagon-wheel_effect

Re: A simple 16x16 dot animation from simple math rules

#58

Post by jakegmaths »

chrisjj wrote: post #31
jakegmaths wrote: post #5

I loved tixy when I first discovered it a few years ago so created this https://www.mathsuniverse.com/tixy (with permission from the original author) with puzzles to solve on the tixy grid. I use it with my computer science students who get really into it.

> In computer graphics, the origin (0, 0) is top-left rather than bottom-left Umm...

I'm struggling to see the problem with this statement, other than maybe to add in the word "usually". My students will know of graphs in maths where the origin is always bottom left. When working with HTML canvas and every other computer graphics situation I've worked in, it's top left instead.

Re: A simple 16x16 dot animation from simple math rules

#59

Post by ForOldHack »

jakegmaths wrote: post #58
chrisjj wrote: post #31

Earlier quoted context omitted.

> In computer graphics, the origin (0, 0) is top-left rather than bottom-left Umm...

I'm struggling to see the problem with this statement, other than maybe to add in the word "usually". My students will know of graphs in maths where the origin is always bottom left. When working with HTML canvas and every other computer graphics situation I've worked in, it's top left instead.

"PostScript uses a coordinate system where the origin is at the bottom-left corner of the page, with the x-axis increasing to the right and the y-axis increasing upwards."

Oscilloscopes use middle-left.

Unreal engine and SketchUp use Screen middle with xy increasing to the right.

in AutoCAD, the user coordinate system is 1/3 of the screen to the left for the origin, with X increasing to the right, and Y increasing upwards.

Almost all raster displays, and memory based programs assume top left, because that is how it was done first - counter intuitive.

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